In the latest of a series of actions designed to accommodate the growth in development of wind energy, the Federal Energy Regulatory Commission today finalized a rule addressing the interconnection requirements for wind power facilities larger than 20 megawatts.

The rule requires transmission providers to append new provisions to the standard agreement and procedures for interconnecting large generating facilities, which are required under their open-access transmission tariffs, in order to address technical requirements and procedures for integrating large wind power facilities into their transmission systems.

"These standard technical requirements and procedures provide just and reasonable terms for the interconnection of wind plants," the order states. "The rule recognizes the technical differences in the design and operational characteristics of wind generating technology, and benefits customers by removing unnecessary obstacles to further development of wind generating resources while ensuring that reliability is protected."

The rule addresses concerns of wind turbine manufacturers and wind power developers who sought standardized interconnection requirements. Having to meet widely varying standards across the country contributes to increased manufacturing costs for wind generators and serves as a barrier to development of this renewable resource.

The final rule provides that wind generators must meet the following conditions, if the transmission service provider demonstrates they are needed. First, if needed, a large wind generating facility must remain operational during voltage disturbances on the grid. Second, large wind plants must, if needed, meet the same technical criteria for providing reactive power to the grid as required of conventional large generating facilities. Third, the final rule provides for supervisory control and data acquisition (SCADA), if needed, to ensure appropriate real-time communications and data exchanges between the wind power producer and the grid operator.

These three requirements will apply only to interconnection agreements signed, filed with the Commission in unexecuted form, or filed as nonconforming agreements, on or after January 1, 2006, or the date six months after publication of the Final Rule in the Federal Register, whichever is later. After these three new requirements take effect, a large wind power plant will have to meet the low voltage ride-through and reactive power standards, but only if the transmission system operator demonstrates they are needed to safely and reliably connect each wind facility to its system.

Other requirements apply immediately when the rule takes effect 60 days after its publication in the Federal Register. Among these other provisions, the Commission allows the wind developer to provide a simplified electrical representation of its large wind farm to the transmission service provider when initially applying to connect with the grid. The wind developer may initially represent the facility, which would be made up of many small induction wind turbines, as a single large equivalent generator. The wind developer has six months from the date of its application to submit completed detailed electric design specifications.

Today's action fleshes out Appendix G of Order No. 2003-A, the Commission's order on rehearing of the final rule standardizing interconnection procedures for large generating facilities. In that order on rehearing about a year and a half ago, the Commission recognized that nonsynchronous large wind generating plants required separate treatment from traditional synchronous generating facilities, and provided for a blank Appendix G to the standard interconnection agreement. Today's final rule spells out the terms of that placeholder Appendix G in the standard large generator interconnection agreement and procedures.

The rule is among a series of actions and technical conferences the Commission has taken to help eliminate barriers to market entry for wind power and to modify Commission requirements to meet the unique characteristics of wind power and other intermittent power production. The Commission initiated an April 13, 2005, rulemaking to make changes necessary to accommodate wind power in the open-access transmission tariffs the Commission provided for in Order No. 888. Wind production has grown by an annual average rate of 20 percent since Order No. 888 was finalized in 1996. Earlier this month, the Commission finalized a small generator interconnection rule for projects less than 20 megawatts, which will help wind and all other smaller generation sources.